Self-locking outlet box connector

ABSTRACT

A connector for securing various types of electrical conduit to various types of electrical fixtures, such as, outlet boxes, which is capable of being applied manually to an opening of a wall of the box or fixture without the use of any tool, and which requires no separate fastening for securing the connector in the wall opening. The connector is secured in the box wall opening by a twisting force exerted thereon, is advanced through the opening by threadlike elements of the connector, and includes teeth or prongs which are brought into engagement with a surface of the wall, surrounding the opening, to retain the connector against detachment from the box opening by a normal twisting force exerted in the opposite direction.

United States Patent [72] Inventor Robert L. Barry 2916 E. RandolphRoad, Silver Spring, Md. 20904 [21] App]. No. 844,802 7 [22] Filed July25,1969 [45] Patented Aug. 17, 1971 [54] SELF-LOCKING OUTLET BOXCONNECTOR 8Claln1s,6Drawlng Figs.

s21 u.s.fl 285/39,

151/37, 174/65 R, 285/219, 285/391 [51] lnt.Cl F161 35/00 [50]FieldoiSearch 174/65 R; 285/219, 158,40, 39, 391; 151/37 561 ReierencesCited UNITED STATES PATENTS 947,185 1/1910 McBeanj. 285/391 X 1,985,32712/1934 Parks 7 285/391 X 3,104,120 9/1963 Myers... 174/65 X 3,306,6382/1967 Rubin 285/158 3,370,631 2/1968 James 151/37 FOREIGN PATENTS488,308 11/1952 Canada 174/65 109,074 1l/1943 Sweden 151/37 PrimaryExaminer-Dave W. Arola Attorney-John N. Randolph ABSTRACT: A connectorfor securing various types of electrical conduit to various types ofelectrical fixtures, such as, outlet boxes, which is capable of beingapplied manually to an opening of a wall of the box or fixture withoutthe use of any tool, and which requires no separate fastening forsecuring the connector in the wall opening. The connector is secured inthe box wail opening by a twisting force exerted thereon, is advancedthrough the opening by threadlike elements of the connector, andincludes teeth or prongs which are brought into engagement .with asurface of the wall, surrounding the opening, to retain the connectoragainst detachment from the box opening by a normal twisting forceexerted in the opposite direction.

SELF-LOCKING OUTLET BOX CONNECTOR SUMMARY It is a primary object of thepresent invention to provide a self-locking connector of extremelysimple construction for attaching armored cable, heavy wall electricalconduit, electrical metalic tubing, nonmetallic flexible cable, rubbercord, plastic conduit and the like, to various electrical fixtures suchas outlet or junction boxes having a wall provided with a connectorreceiving opening.

More particularly, it is an object of the invention to provide aconnector which can be secured in a wall opening of electrical fixturesby a manual twisting force imparted thereto, without the use of any tooland without the use of a separate fastening.

Another object of the invention is to provide a connector having meansto resist disengagement thereof from the wall opening by a twistingforce imparted thereto in the opposite direction. Still another objectof the invention is to provide a connector having integral threadlikemeans for advancing a part of the connector through the wall openingwhen a twisting force in one direction is imparted thereto, and integralmeans cooperating therewith and with said threadlike elements forgripping the wall around the opening, to resist turning of the connectorin an opposite direction and which would result in the detachment of theconnector from the box.

Various other objects and advantages of the invention will hereinafterbecome more fully apparent from the following description of thedrawing, illustrating presently preferred embodim'ents thereof, andwherein:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an end-elevational viewlooking toward an outer end of the connector and showing it applied to awall of an outlet or junction box;

FIG. 2 is a top plan view thereof;

FIG. 3 is a substantially central vertical sectional view takenlongitudinally through the connector, substantially along a plane asindicated by the line 3-3 of FIG. 1;

FIG. 4 is an end-elevational view, partly broken away looking toward theother, inner end of the connector, taken substantially along a plane asindicated by the line 4-4 of- FIG. 2;

a FIG. 5 is a top plan view, with certain of the parts omitted, of aslightly modified embodiment of the connector; and

FIG. 6 is a similar view of a second modified form thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more specifically tothe drawing and first with reference to FIGS. 1 through 4, theconnector, designated generally 8, as illustrated therein and comprisingthe invention, includes an elongated unitary body 9 having a ringshapedintermediate portion 10, a tubular neck 11 which project from one sideof the ring portion 10, and a plate member 12 which projects from theopposite side of said ring portion.

The tubular neck 11 projects from a front face 13 of the member and hasa bore 14 which registers with the opening 15 of ring member 10. Theneck 11 is of frustoconical shape both externally and internally thereofso that the bore 14 and the exterior surface 16 of said neck both taperaway from the ring member 10. Said exterior surface 16 has a helical ribor thread 17 preferably composed of more than one but less than twoconvolutions one end of which terminates at the restricted or outerforward end of the neck 11 and the other end of which is spaced from thefront face 13. Said front face 13'is provided with circumferentiallyspaced apart radially elongated teeth or prongs 18 which may be struckup from the surface of said face 13 and all of which are inclined in thesame direction, clockwise as illustrated in the frontelevational view,FIG. 4.

The plate 12 is of a width approximately equal to the diameter of thering member 10, as seen in FIGS. 1 and 2, and includes a downwardlybowed intermediate portion 19 of approximately semicircular shape incross section or end elevation, to provide a channel 20 which alignswith the bottom half of the opening 15. The plate 12 includessubstantially flat coplanar side edge portions 21 forming wings for apurpose which will hereinafter be described.

The connector 8 includes a clamping plate 22 having a forward portion23, as seen in FIG. 2, of a width corresponding to the width of theplate member 12, and a rear portion 24 of a reduced width but of a widthsufficient to bridge the channel 20. The front portion 23, adjacent itslateral ends has unthreaded openings 25, FIG. 1, to register withthreaded openings 26 of the wings 21 to receive clamping screws 27 bywhich the clamping plate 22 is attached to the plate 12. One or moreribs 28 project from the underside of the plate 22 and extend crosswisethereof and may be embossed in said plate, as illustrated. The plate 22has an upturned flange 29 at its forward end which bears against aportion of the rear face 30 of the ring member 10 and which is of a sizeto cover the upper half of the opening 15.

A portion of one form of electrical conduit 31, such as a conventionalnonmetallic flexible cable, is illustrated in the drawing extendinglongitudinally through the connector 8. The conduit 31 is passed throughthe connector 8 before the clamping plate 22 is attached to the plate 12and positioned with an end thereof disposed at a desired distance beyondthe neck 11. The clamping plate 22 is then applied and the fastenings 27tighten sufficiently to cause the ribs 28 to be pressed into the casingof the conduit for clamping said conduit immovably in the channel 20.

The neck 11 is then inserted inwardly through the knockout opening 32 ofa wall 33, of an outlet box or other conventional electrical fixture.The diameter of the forward end of the neck 11 is sufficiently smallerthan the opening 32 so that the forward end of the thread or rib 17 canpass through said opening. However, the inner end of the thread 17,which is located adjacent the front face 13, is of a diameter greaterthan the diameter or the opening 32 so that a twisting force must beexerted on the connector 9 to advance the neck 11 from left to rightthrough the opening 32 to its position of FIG. 3. This twisting force isimparted manually, without the use of any tool, by the fingers of theoperator engaging the wings 21 for turning the connector clockwise, asseen in FIG. 1, usually through an arc of approximately or a halfrevolution. As the front face 13 approaches the outer surface of thewall 33, the teeth or prongs 18 will contact said outer wall surface andwill be deflected toward positions more nearly parallel to the face 13and will assume positions imbedded in the outer surface of the wall 33,to resist rotation of the connector 9 in the opposite direction orcounterclockwise, as seen in FIG. 1, for detaching the connector 9 fromthe wall 33, Thus, as illustrated in FIGS. 2 and 3, when the connectoris applied, a part of the wall 33, surrounding the opening 32, isclamped between a part of the rib or thread 17 and the teeth 18. Theperiphery of the ring member 10 may be provided with wrench lands 34 toreceive a wrench or other tool, not shown, to facilitate detachment ofthe connector 9 from the wall 33, should this be necessary.

It will be noted that the connector 9 is applied and securely fastenedto the wall 33 without the use of any tool and without requiring theapplication of any form of fastening to the neck 1 l for retaining saidneck in the opening 32.

The portion of the plate 22, covering the channel 20, could be upwardlybowed to accommodate electrical conduits of larger cross-sectionalsizes. I

FIG. 5 illustrates a slightly modified embodiment of the connector,designated generally 35, the clamping plate of which has been omitted,since it corresponds with the clamping plate 22. The body 36 of theconnector 35 differs from the body 9 of the connector 8 only in that theneck 37 is provided with interrupted, circumferentially spaced spiralribs or thread portions 38in lieu of the helical rib or thread 17 Theconnector 35 is I distances from the forward end of the neck 40, whichare spirally inclined and which have substantially flat and spirallyinclined inner faces 42which are spaced different distances from thefront face 43, which corresponds to the face 13, and

each of which is disposed at an incline relative to the plane of saidface 43. Thus, the connector 39. will be secured in a knockout openingof a fixture wall by a twisting force manually imparted thereto in thesame manner as the connector 8 and with the lug faces 42 performing thesame function as the rib 17. The connectors 35 and 39 are applied by atwisting force in the same direction as the connector 8.

Various modifications and changes are contemplated and may be resortedto without departing from the function or scope of the invention.

lCLAlM AS MY INVENTION:

1. A connector for securing an electrical conduit to an electricalfixture comprising, an elongated body having a ringshaped intermediateportion provided with a front face and a rear face, a tubular neckprojecting from said front face'and having an exterior surface ofsmaller diameter than the ring portion and which tapers uniformly fromsaid front face outwardly to a forward end thereof, means embossed onsaid exterior surface of the neck adapted to advance the neck through anopening of an electrical fixture wall when a twisting force is impartedin one direction to said body for positioning a part of the fixturewall, surrounding said opening,

between a part of said means and said front face, manually engageablemeans extending from said rear face and adapted to be manually engagedfor imparting the twisting force to the body member for advancing theneck through the fixture opening, a clamping member adjustably securedto said manually engageable means and combining therewith to from apassage communicating with the opening of the ring portion and thehollow neck through which an electrical conduit is adapted to extend andin which a part of the conduit is clamped in said passage, and resilientteeth projecting from ,said front face, said teeth beingcircumferentially spaced from each other a distance at least equal totwice their circumferential thickness and wherein said connector andwall are so constructed arranged that said teeth are caused to flex byengagement with said wall when saidconnector is turned in said onedirection and embedded in the fixture wall when said connector is turnedin a direction opposite said one direction.

2. A connector as in claim 1, said teeth being inclined in a directionopposite to the direction of rotation of the body for advancing the neckthrough the fixture opening.

3. A connector as in claim 1, said means embossed on the 5. A connectoras in claim 1, said means embossed on the.

neck comprising circumferentially spaced spirally arranged lugs havinginner faces facing toward said front face, inclined relative thereto andspaced different distances therefrom.

6. A connector as in claim '1, said manually engageable means comprisinga plate having an intermediate portion of arcuate cross section defininga channel disposed in alignment with a least a part of the hollowinteriors of the ring portion and neck and in which the electricalconduit is received, and substantially flat coplanar side edge portionsforming wings adapted to be engaged for imparting torque manually to thebody.

7. A connector as in claim 6, said clamping member com-

1. A connector for securing an electrical conduit to an electricalfixture comprising, an elongated body having a ringshaped intermediateportion provided with a front face and a rear face, a tubular neckprojecting from said front face and having an exterior surface ofsmaller diameter than the ring portion and which tapers uniformly fromsaid front face outwardly to a forward end thereof, means embossed onsaid exterior surface of the neck adapted to advance the neck through anopening of an electrical fixture wall when a twisting force is impartedin one direction to said body for positioning a part of the fixturewall, surrounding said opening, between a part of said means and saidfront face, manually engageable means extending from said rear face andadapted to be manually engaged for imparting the twisting force to thebody member for advancing the neck through the fixture opening, aclamping member adjustably secured to said manually engageable means andcombining therewith to from a passage communicating with the opening ofthe ring portion and the hollow neck through which an electrical conduitis adapted to extend and in which a part of the conduit is clamped insaid passage, and resilient teeth projecting from said front face, saidteeth being circumferentially spaced from each other a distance at leastequal to twice their circumferential thickness and wherein saiDconnector and wall are so constructed arranged that said teeth arecaused to flex by engagement with said wall when said connector isturned in said one direction and embedded in the fixture wall when saidconnector is turned in a direction opposite said one direction.
 2. Aconnector as in claim 1, said teeth being inclined in a directionopposite to the direction of rotation of the body for advancing the neckthrough the fixture opening.
 3. A connector as in claim 1, said meansembossed on the neck comprising a helical rib or thread.
 4. A connectoras in claim 1, said means embossed on the neck comprisingcircumferentially spaced spirally extending interrupted threads.
 5. Aconnector as in claim 1, said means embossed on the neck comprisingcircumferentially spaced spirally arranged lugs having inner facesfacing toward said front face, inclined relative thereto and spaceddifferent distances therefrom.
 6. A connector as in claim 1, saidmanually engageable means comprising a plate having an intermediateportion of arcuate cross section defining a channel disposed inalignment with a least a part of the hollow interiors of the ringportion and neck and in which the electrical conduit is received, andsubstantially flat coplanar side edge portions forming wings adapted tobe engaged for imparting torque manually to the body.
 7. A connector asin claim 6, said clamping member comprising a plate disposed over saidchannel having lateral extensions overlying parts of said wings, andthreaded fastenings adjustably securing said lateral extensions to thewings.
 8. A connector as in claim 7, said plate having transverse ribson its under side adapted to be embedded in the electrical conduit foranchoring the conduit to the connector body.